Multiple choice

Directions: Identify the correct alternative that completes the series. 25, 27, 31, 39, ?, 87, 151

  1. 31

  2. 27

  3. 55

  4. 151
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C Correct answer
Explanation

The series follows a pattern of adding powers of 2: 25+2=27, 27+4=31, 31+8=39, 39+16=55, 55+32=87, 87+64=151. The missing number is 55.

AI explanation

The differences between the consecutive terms are powers of 2: 27 - 25 = 2, 31 - 27 = 4, and 39 - 31 = 8. The next difference should be 16, making the missing term 39 + 16. This equals 55, and checking the next step confirms that 55 + 32 equals 87.

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